fix: 修复语法错误和导入问题

main.py

@@ -466,11 +466,6 @@ async def handle_matrix_message(action: str, conversation_id: str = None, user_m
             await matrix_bot.send_message(room_id, f"处理消息时出错: {str(e)}")
         finally:
             db.close()
-    
-    except Exception as e:
-        logger.error(f"处理Matrix消息失败: {e}")
-    finally:
-        db.close()
 
 
 # ==================== 启动和关闭 ====================

services/matrix_service.py

@@ -201,4 +201,8 @@ class MatrixBot:
                 await self.client.close()
             except:
                 pass
-            self.is_running = False
+            self.is_running = False
+
+
+# 全局实例
+matrix_bot = MatrixBot()